CVE-2024-23322: Envoy crashes when idle and request per try timeout occur within the backoff interval
Noroxi assessment
Priority: Monitor (action score 30/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.67% (FIRST EPSS); higher than 52.1% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- No fixed version is recorded, but the references include a patch (commit or PR) link.
Low priority for now. See the fix and affected versions sections below.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Envoy is a high-performance edge/middle/service proxy. Envoy will crash when certain timeouts happen within the same interval. The crash occurs when the following are true: 1. hedge_on_per_try_timeout is enabled, 2. per_try_idle_timeout is enabled (it can only be done in configuration), 3. per-try-timeout is enabled, either through headers or configuration and its value is equal, or within the backoff interval of the per_try_idle_timeout. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- Published
- Feb 9, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.6% · 52th percentile
- CWE
- CWE-416
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.6%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.5
- CNA · GitHub_M
- 7.5
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| envoyproxy | envoy | cpe:2.3:a:envoyproxy:envoy |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- envoyproxy envoy1.26.0 and later · before 1.26.7
- envoyproxy envoy1.27.0 and later · before 1.27.3
- envoyproxy envoy1.28.0 and later · before 1.28.1
- envoyproxy envoy1.29.0 and later · before 1.29.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
envoyproxy envoy
- >= 1.29.0, < 1.29.1, >= 1.28.0, < 1.28.1, >= 1.27.0, < 1.27.3, < 1.26.7affected
Same product
envoyproxy: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-30255HTTP/2: CPU exhaustion due to CONTINUATION frame flood56Plan
- CVE-2024-27919HTTP/2: memory exhaustion due to CONTINUATION frame flood56Plan
- CVE-2021-29492Bypass of path matching rules using escaped slash characters52Plan
Published before and after this one in the same product
- ← EarlierCVE-2023-35943Jul 25, 2023 · Envoy vulnerable to CORS filter segfault when origin header is removed30Monitor
- ← EarlierCVE-2023-35944Jul 25, 2023 · Envoy vulnerable to incorrect handling of HTTP requests and responses with mixed case schemes21Monitor
- Later →CVE-2024-23323Feb 9, 2024 · Excessive CPU usage when URI template matcher is configured using regex in Envoy21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2024-39305143 days apartEnvoy Proxy use after free when route hash policy is configured with cookie attributes36Monitor
- CVE-2024-32974116 days apartEnvoy affected by a crash in EnvoyQuicServerStream::OnInitialHeadersComplete()30Monitor
- CVE-2023-35943199 days apartEnvoy vulnerable to CORS filter segfault when origin header is removed30Monitor
- CVE-2023-35942199 days apartEnvoy's gRPC access log crash caused by the listener draining26Monitor
- CVE-2024-34362116 days apartEnvoy affected by a crash (use-after-free) in EnvoyQuicServerStream23Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-416 · Use After FreeCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Root cause
After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.
The bug in code
The whole CWE-416 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
free(dev->buf);
/* ... another thread is still running ... */
process(dev->buf);Fixed
lock(&dev->lock);
free(dev->buf);
dev->buf = NULL;
unlock(&dev->lock);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.